ming: i believe you are correct about the "not enough power causing system restart". if anything.... the system restarting due to not enough power would probably wind up turning into an infinite loop of restarts at that point, since it takes more power to get the computer running than it does to KEEP it running. and it could possibly result in the PSU and/or a component or two taking the fall as well. happened when i had a GeForce 4 Ti4200 in my Sony Vaio. woke up to artifacts all over the screen on the windows desktop.... restarted my computer..... never saw a single graphic on that card again. *sniffle* i still have the card too.
as they said... 350 watts should be good, as long as it's a good brand name power supply.... not one that you'd buy from your local wal-mart or anything like that. Antec would be good for one.... not sure about others. probably wouldn't hurt to go higher if you can... maybe even 500 watts..... just in case you happen to upgrade further down the line... won't have to worry about buying ANOTHER power supply, unless you build a whole 'nother computer. just remember to get one that is good quality and a good brand name. if you want..... if you find one that you think is good, post a link to it in here so we can look at it, see what it is/what it's like, and give you a thumbs up or thumbs down as to whether or not to go through with the purchase of the power supply.